Silicone compositions of the condensation cure type are used as sealing agents, adhesives, coating agents or potting agents in a wide variety of areas including buildings, constructions, electric and electronic equipment and components, transporting vehicles, electric appliances and the like. Most of the silicone-based sealing, adhesive, coating or potting compositions of the condensation cure type used in these applications use organosilicon compounds containing at least three silicon-bonded hydrolyzable radicals in the molecule and/or partial hydrolyzates thereof as the crosslinker. These organosilicon compounds essentially refer to trifunctional hydrolyzable silanes and/or partial hydrolyzates thereof, examples of which include alkyltrimethoxysilanes, alkyltributanoximesilanes, alkyltriacetoxysilanes, and alkyltriisopropenoxysilanes or partial hydrolyzates thereof. Of these compositions, corrosion and safety aspects place greater concerns on one-part, alcohol-release type, room temperature-curable organopolysiloxane compositions using alcohol-releasable crosslinkers.
In the application where transparency is required, RTV organopolysiloxane compositions generally rely on tin-based catalysts rather than titanium-based catalysts which tend to give rise to a discoloration problem. The tin compounds, however, induce degradation of siloxane chains by alcohol so that the compositions become less curable during long-term sealed storage in the uncured state. In order to improve the shelf stability, it is well known to use alcohol scavengers as typified by silazane compounds having an Si—N bond. The use of such scavengers, however, tends to detract from adhesion.
Also in the sealant application, compositions having improved adhesion as well as rubber elasticity are generally desired.
Reference should be made to Dziark, U.S. Pat. No. 4,417,042 (JP-B 4-13382), Wengrovius et al., U.S. Pat. No. 4,863,992 (JP-A 1-113429), JP-A 11-189720, JP-A 2000-7918 and JP-B 7-81079.